Disodium 2,2'-[(9,10-dihydro-5,8-dihydroxy-9,10-dioxo-1,4-anthrylene)diimino]bis[5-tert-butylbenzenesulphonate]

Biodegradation in water: screening tests

Administrative data

Endpoint:

biodegradation in water: inherent biodegradability

Type of information:

experimental study

Adequacy of study:

key study

Study period:

From April 16 to May 14, 1991

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1991

Report date:

1991

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 302 B (Inherent biodegradability: Zahn-Wellens/EMPA Test)

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Sodium 3,3'-(9,10-dioxoanthracene-1,4-diyldiimino)bis(2,4,6-trimethylbenzenesulphonate)

EC Number:

224-748-4

EC Name:

Sodium 3,3'-(9,10-dioxoanthracene-1,4-diyldiimino)bis(2,4,6-trimethylbenzenesulphonate)

Cas Number:

4474-24-2

Molecular formula:

C32H30N2O8S2.2Na

IUPAC Name:

disodium 3,3'-[(9,10-dioxo-9,10-dihydroanthracene-1,4-diyl)diimino]bis(2,4,6-trimethylbenzenesulfonate)

Test material form:

solid: particulate/powder

Study design

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge (adaptation not specified)

Details on inoculum:

- Source of inoculum/activated sludge: the aeration stage of the Severn Trent Plc sewage treatment plant at Belper, Derbyshire, treating predominantly domestic sewage.
- Pretreatment: The sample was maintained at 21°C with continuous aeration and washed by settlement and resuspension in test medium prior to use.
Equivalent to 1.0 g dry weight/l.

Duration of test (contact time):

28 d

Initial test substance concentration

Initial conc.:

ca. 100 mg/L

Based on:

act. ingr.

Parameter followed for biodegradation estimation

Parameter followed for biodegradation estimation:

DOC removal

Details on study design:

Temperature: 22°C ± 1°C
Lighting: the test was conducted in darkness
Evaporation: Losses by evaporation were made good by the addition of deionised water immediately prior to sampling.
Sampling: Aeration of the test vessels was stopped and the contents of the vessels allowed to Bettle for 20 minutes. Samples (appoximately 20 ml) were withdrawn from the supernatent and centrifuged at 3900 rpm for 15 minutes to remove any further suspended solids. Samples were analysed immediately. Samples were taken at O and 3 hours and an Days 7, 14, 21, 27 and 28 for dissolved organic carbon and spectrophotometric analysis.

Reference substance

Reference substance:

diethylene glycol

Results and discussion

% Degradation

Parameter:

% degradation (DOC removal)

Value:

> 4 - < 16

Sampling time:

28 d

BOD5 / COD results

Results with reference substance:

Diethylene glycol attained 100 % degradation within 14 days.

Any other information on results incl. tables

pH values did not drop below 5.2 in any culture vessel during the course of the study and were readjusted to between pH 7 and 8 daily. Dissolved oxygen levels remained at approximately 7.4 mg O2/l or above in all culture vessels at all times.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Interpretation of results:

not inherently biodegradable

Conclusions:

The DOC removal of Acid Blue 80 was between 4 % and 16 % in 28 d. The substance is not inherently biodegradable.